PatriYacht

That's a good thick block. It's good for another overbore after this one. And then you put in the 4.25 stroke crank ......

Boatally Insane

.....AND a blower!!!



I'm thinkin' this build will be enough for now...

My last build made just shy of 600 hp and got me to 80.5 mph... (I only have 21' of hull)

This time 'round I'm running a little more compression, AFR heads and a bit bigger "Rmbuilder" cam... Hopefully it'll be close to 650 hp or so..


Oh, I also just installed a Stern Jack.. should be fun!!


Doug

TylerCrockett

I bore the Gen 6 502's to 4.600. We ran the same engine for 2 straight racing seasons. When I put the torque plates back on and rehone the cylinders they clean right up.

Young Performance

Same here. Can't even begin to remember how many I have bored to 4.600. Have never had the first bit of trouble out of one of them. Eddie

Pismo10

Sorry to ask but, What happened that the engine needs rebuilding after only 2-3 years?

Boatally Insane

....Well, actually it only ran about an hour this time...

It's a llooong story but I'll try to condense it some..

I had 90 hours on the engine so I decided to check the valve springs and found they were going soft so I bought an "on the engine" valve spring compressor and was using air pressure to hold the valves in place while I changed out the springs.
I did the even side of the the engine and had no problems whatsoever. When I was in the process of changing the springs on the # 3 cylinder I felt air blowing on my leg.. Much to my surprise it was comming out of the # 5 spark plug hole. I then put the air hose on the # 5 cylinder and air came out of the # 7 spark plug hole..

I pulled the head to find that the head gasket was just starting to blow between the cylinders....
Turns out my engine "builder" had used stock head gaskets...

Well, I'm not one to leave well enough alone and a friend of mine happened to have a set of AFR heads for sale for a good price so I figure I might as well "freshen" the whole engine and change the cam to better compliment the new heads.
I had the block decked and had the crank checked out and everything was good.
I assembled the engine myself THIS time and threw it back in the boat and took it over to
Full Throttle Marine to run on his propshaft dyno.
The first pull we were just taking it easy on it and it made 515 hp at 5000 rpm at the prop.
The next pull it was down 50 hp and wouldn't pull over 5000 rpm. We checked EVERYTHING and finally I pulled a valve cover to check valve adjustment and found that the oil was FULL of metal.


I pulled the engine and found 6 spun rod bearings and metal EVERYWHERE.
Still not exactly sure what went wrong but we're still working on figuring that out..
My crank, rods, and pistons are junk and my block needs to be bored...



Doug

BGIII

Sounds like it's time for a 540 Doug!

Strip Poker 388

What about in a blower aplication?

Pismo10

I think there are differences as to how far you can bore based on Bulldog vs Dart vs regular block.

Boatally Insane

I wish I could swing it.. I could if I sat out yet another season but that just ain't happenin'

I priced an assembled 540 shortblock from Rehyer Morrison and by the time I got yet another new cam and everything else needed I'd have $7500 in it using my heads and intake...


I have it at the machine shop right now on it's way back together..
I got a crank from Kidnova (THANKS AGAIN BILL )
It'll have Eagle rods with the l-19 bolts and JE pistons.
I also got a 10 quart pan off Ebay ..

Everything said and done I'll get it back together for around $4200.... should be done and back on the water sometime in January.

Doug